> const { parsePatch } = require('./libcjs');
undefined
> parsePatch('--- x\u2028x')

<--- Last few GCs --->

[87253:0x45b0d000]    37408 ms: Mark-Compact 4051.2 (4131.1) -> 4042.3 (4138.1) MB, pooled: 0 MB, 972.26 / 0.00 ms  (average mu = 0.160, current mu = 0.127) allocation failure; scavenge might not succeed
[87253:0x45b0d000]    38452 ms: Mark-Compact 4058.0 (4138.1) -> 4046.7 (4142.6) MB, pooled: 0 MB, 1037.85 / 0.00 ms  (average mu = 0.114, current mu = 0.006) allocation failure; scavenge might not succeed


<--- JS stacktrace --->

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
----- Native stack trace -----

 1: 0xe36196 node::OOMErrorHandler(char const*, v8::OOMDetails const&) [node]
 2: 0x123f4a0 v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, v8::OOMDetails const&) [node]
 3: 0x123f777 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, v8::OOMDetails const&) [node]
 4: 0x146d1a5  [node]
 5: 0x146d1d3  [node]
 6: 0x148628a  [node]
 7: 0x1489458  [node]
 8: 0x1cc6071  [node]
Aborted (core dumped)

if ((/^(Index:\s|diff\s|---\s|\+\+\+\s|===================================================================)/).test(line)) {
        break;

const fileHeader = (/^(---|\+\+\+)\s+(.*)\r?$/).exec(diffstr[i]);
if (fileHeader) {
  ...